Holding a tube stationary inside another tube, such as in a catheter tube, to prevent it from sliding without totally collapsing the fluid path has always been somewhat problematic. One device commonly used in the medical industry to solve this problem has been the use of a Touhy Borst adapter, such as those described in U.S. Pat. Nos. 5,795,307 and 5,320,613. A conventional Touhy Borst adapter is an active valve that is used for attaching catheters to various other devices and has particular utility where a user needs to provide a seal under changing conditions. Touhy Borst valves typically include an O-ring-type element or grommet, usually silicone or rubber, that is seated in a socket forming part of a main passage between an outer wall and a hollow screw mechanism. In operation, a cap threaded on the end of the passage contains a spigot that actively compresses the O-ring or grommet when the cap is selectively rotated to drive the spigot axially inward. The resulting compression closes down the opening in the O-ring around the catheter to prevent “flow-by.” When a catheter is absent, the O-ring can be closed down enough to completely close off the opening in the main passage. The compression of the O-ring or grommet in a fixed space does not allow outward expansion and effectively reduces the internal diameter of the O-ring or grommet, which restricts movement of tubing positioned inside the O-ring or grommet.
While conventional Touhy Borst adapters are effective to reduce movement of tubing, the screw mechanism in the Touhy Borst adapter is usually required to be manually turned several times, which is generally a two-handed operation. Touhy-Borst adapters also undesirably require manipulation in order to match the desired diameter of the O-ring or grommet opening to the outside diameter of the catheter. This can be problematic because if a Touhy Borst adapter it is not tightened sufficiently, the valve will leak and blood may flow by the valve. However, if the Touhy Borst adaptor is turned too tight, it may be more difficult to insert the catheter due to friction between the catheter and the grommet or the catheter could be crushed. In addition, the screw mechanism can be over-tightened, which may collapse the tubing being held by the adapter. Further, although Touhy Borst adapters can be used for securing or sealing two tubes relative to each other under low pressures, at higher pressures the adapter needs to be tighter, and more force has to be applied to the tubing with the attendant risk of damage to the tubing being held. Thus, conventional Touhy Borst adapters can be problematic when procedures such as CT injections and sclerotherapy injections are conducted at high pressures, for example, from 200 to 800 PSI.
Other types of valves, such as hemostasis valves, that seal the space between two tubes are well known in the art, but such valves are typically limited to low pressure seals, usually less than 100 PSI. Also, hemostasis valves do not clamp two tubes together, thereby allowing one tube to slide freely within another tube, unless a mechanical device such as a luer lock physically locks them in place. Hemostasis valves do not allow for variable positions, which is required in procedures such as sclerotherapy. In the sclerotherapy procedure, blood vessels are treated by injecting medicine into the vessels, which makes them shrink. This procedure is often used to treat varicose veins. Thus, a device is needed that is capable of functioning under high pressures that can selectively lock a catheter in place and prevent inadvertent disconnections, while allowing variability in position between two tubes, such that they can slide freely in relation to each other.
A device has not yet been proposed that solves all of the above-mentioned problems. A locking clamp that can be used to keep catheter tubing stationary and prevent it from sliding around under high pressures, such as occurs during CT injections or sclerotherapy, is provided herein.
Various other purposes and embodiments of the present invention will become apparent to those skilled in the art as more detailed description is set forth below. Without limiting the scope of the invention, a brief summary of some of the claimed embodiments of the invention is set forth below. Additional details of the summarized embodiments of the invention and/or additional embodiments of the invention may be found in the Detailed Description.